Wogonin Improves Histological and Functional Outcomes, and Reduces Activation of TLR4/NF-κB Signaling after Experimental Traumatic Brain Injury

Traumatic brain injury (TBI) initiates a neuroinflammatory cascade that contributes to neuronal damage and behavioral impairment. This study was undertaken to investigate the effects of wogonin, a flavonoid with potent anti-inflammatory properties, on functional and histological outcomes, brain edema, and toll-like receptor 4 (TLR4)- and nuclear factor kappa B (NF-κB)-related signaling pathways in mice following TBI.Mice subjected to controlled cortical impact injury were injected with wogonin (20, 40, or 50 mg·kg(-1)) or vehicle 10 min after injury. Behavioral studies, histology analysis, and measurement of blood-brain barrier (BBB) permeability and brain water content were carried out to assess the effects of wogonin. Levels of TLR4/NF-κB-related inflammatory mediators were also examined. Treatment with 40 mg·kg(-1) wogonin significantly improved functional recovery and reduced contusion volumes up to post-injury day 28. Wogonin also significantly reduced neuronal death, BBB permeability, and brain edema beginning at day 1. These changes were associated with a marked reduction in leukocyte infiltration, microglial activation, TLR4 expression, NF-κB translocation to nucleus and its DNA binding activity, matrix metalloproteinase-9 activity, and expression of inflammatory mediators, including interleukin-1β, interleukin-6, macrophage inflammatory protein-2, and cyclooxygenase-2.Our results show that post-injury wogonin treatment improved long-term functional and histological outcomes, reduced brain edema, and attenuated the TLR4/NF-κB-mediated inflammatory response in mouse TBI. The neuroprotective effects of wogonin may be related to modulation of the TLR4/NF-κB signaling pathway

Correlation of ultrastructural changes of endothelial cells and astrocytes occuring during blood brain barrier damage after traumatic brain injury with biochemical markers of BBB leakage and inflammatory response

Focal cerebral contusion can be dynamic and expansive. It has been proved that subsequent expansive contusion is caused by brain parenchyma damage, especially BBB damage. We investigated a group of patients with traumatic brain injury. The patients (n=18) were divided into group I (n=7) of patients submitted to neurosurgery due to expansive contusion, and group II (n=11) of patients without surgery. Serum concentrations of NSE and S-100B protein were measured by electrochemiluminescence immunoassay, interleukin-6 (IL-6) was measured by chemiluminescent sequential immunometric assay and matrix metalloproteinases (MMP-9, MMP-2) were measured by immunoassays. Cortical biopsy specimens of brain were investigated by electron microscopy in patients with trauma brain injury submitted to neurosurgery. Biochemical investigation from first day up to third day after traumatic brain injury proved increased values of IL-6 (302.2±119.9 vs. 59.6±11.9 ng/l, p&lt;0.02) and S-100B protein (3.064±1.064 vs. 0.649±0.182 μg/l, p&lt;0.05) in patients with expansive lesion compared to patients without expansive contusion. Significantly higher levels of MMP-9 (150.4±28.46 vs. 74.11±13.16 ng/l, p&lt;0.05) and of MMP-2 (814.5±126.3 vs. 523.1±25.28 ng/l, p&lt;0.05) were found during first 3 days after admission in group I compared to group II. MMP-9 has also elevated in group II from lower values after admission (74.11±13.16 ng/l) up to high levels on the 10th day of hospitalization (225.1±49.35 ng/l). Ultrastructural investigation of endothelial cells and surrounded tissue revealed perivascular hemorrhage, increased pinocytic activity of endothelial cells, and cytotoxic edema of astroglial cells. Multivesical bodies were disclosed inside the endothelial cells. Higher levels of serum protein S-100B and IL-6 correlated with ultrastructural changes of endothelial cells, and with inflammatory response following TBI, respectively.</jats:p